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<div class="fragment"><div class="line"><a name="l00001"></a><span class="lineno">    1</span>&#160;<span class="comment">/**</span></div>
<div class="line"><a name="l00002"></a><span class="lineno">    2</span>&#160;<span class="comment"> * Copyright (c) 2015-present, Facebook, Inc.</span></div>
<div class="line"><a name="l00003"></a><span class="lineno">    3</span>&#160;<span class="comment"> * All rights reserved.</span></div>
<div class="line"><a name="l00004"></a><span class="lineno">    4</span>&#160;<span class="comment"> *</span></div>
<div class="line"><a name="l00005"></a><span class="lineno">    5</span>&#160;<span class="comment"> * This source code is licensed under the BSD+Patents license found in the</span></div>
<div class="line"><a name="l00006"></a><span class="lineno">    6</span>&#160;<span class="comment"> * LICENSE file in the root directory of this source tree.</span></div>
<div class="line"><a name="l00007"></a><span class="lineno">    7</span>&#160;<span class="comment"> */</span></div>
<div class="line"><a name="l00008"></a><span class="lineno">    8</span>&#160;</div>
<div class="line"><a name="l00009"></a><span class="lineno">    9</span>&#160;<span class="comment">// from Nvidia cuDNN library samples; modified to compile within faiss</span></div>
<div class="line"><a name="l00010"></a><span class="lineno">   10</span>&#160;</div>
<div class="line"><a name="l00011"></a><span class="lineno">   11</span>&#160;<span class="preprocessor">#pragma once</span></div>
<div class="line"><a name="l00012"></a><span class="lineno">   12</span>&#160;<span class="preprocessor"></span></div>
<div class="line"><a name="l00013"></a><span class="lineno">   13</span>&#160;<span class="keyword">namespace </span>faiss { <span class="keyword">namespace </span>gpu {</div>
<div class="line"><a name="l00014"></a><span class="lineno">   14</span>&#160;</div>
<div class="line"><a name="l00015"></a><span class="lineno">   15</span>&#160;<span class="comment">/*</span></div>
<div class="line"><a name="l00016"></a><span class="lineno">   16</span>&#160;<span class="comment"> * Copyright 1993-2014 NVIDIA Corporation.  All rights reserved.</span></div>
<div class="line"><a name="l00017"></a><span class="lineno">   17</span>&#160;<span class="comment"> *</span></div>
<div class="line"><a name="l00018"></a><span class="lineno">   18</span>&#160;<span class="comment"> * NOTICE TO LICENSEE:</span></div>
<div class="line"><a name="l00019"></a><span class="lineno">   19</span>&#160;<span class="comment"> *</span></div>
<div class="line"><a name="l00020"></a><span class="lineno">   20</span>&#160;<span class="comment"> * This source code and/or documentation (&quot;Licensed Deliverables&quot;) are</span></div>
<div class="line"><a name="l00021"></a><span class="lineno">   21</span>&#160;<span class="comment"> * subject to NVIDIA intellectual property rights under U.S. and</span></div>
<div class="line"><a name="l00022"></a><span class="lineno">   22</span>&#160;<span class="comment"> * international Copyright laws.</span></div>
<div class="line"><a name="l00023"></a><span class="lineno">   23</span>&#160;<span class="comment"> *</span></div>
<div class="line"><a name="l00024"></a><span class="lineno">   24</span>&#160;<span class="comment"> * These Licensed Deliverables contained herein is PROPRIETARY and</span></div>
<div class="line"><a name="l00025"></a><span class="lineno">   25</span>&#160;<span class="comment"> * CONFIDENTIAL to NVIDIA and is being provided under the terms and</span></div>
<div class="line"><a name="l00026"></a><span class="lineno">   26</span>&#160;<span class="comment"> * conditions of a form of NVIDIA software license agreement by and</span></div>
<div class="line"><a name="l00027"></a><span class="lineno">   27</span>&#160;<span class="comment"> * between NVIDIA and Licensee (&quot;License Agreement&quot;) or electronically</span></div>
<div class="line"><a name="l00028"></a><span class="lineno">   28</span>&#160;<span class="comment"> * accepted by Licensee.  Notwithstanding any terms or conditions to</span></div>
<div class="line"><a name="l00029"></a><span class="lineno">   29</span>&#160;<span class="comment"> * the contrary in the License Agreement, reproduction or disclosure</span></div>
<div class="line"><a name="l00030"></a><span class="lineno">   30</span>&#160;<span class="comment"> * of the Licensed Deliverables to any third party without the express</span></div>
<div class="line"><a name="l00031"></a><span class="lineno">   31</span>&#160;<span class="comment"> * written consent of NVIDIA is prohibited.</span></div>
<div class="line"><a name="l00032"></a><span class="lineno">   32</span>&#160;<span class="comment"> *</span></div>
<div class="line"><a name="l00033"></a><span class="lineno">   33</span>&#160;<span class="comment"> * NOTWITHSTANDING ANY TERMS OR CONDITIONS TO THE CONTRARY IN THE</span></div>
<div class="line"><a name="l00034"></a><span class="lineno">   34</span>&#160;<span class="comment"> * LICENSE AGREEMENT, NVIDIA MAKES NO REPRESENTATION ABOUT THE</span></div>
<div class="line"><a name="l00035"></a><span class="lineno">   35</span>&#160;<span class="comment"> * SUITABILITY OF THESE LICENSED DELIVERABLES FOR ANY PURPOSE.  IT IS</span></div>
<div class="line"><a name="l00036"></a><span class="lineno">   36</span>&#160;<span class="comment"> * PROVIDED &quot;AS IS&quot; WITHOUT EXPRESS OR IMPLIED WARRANTY OF ANY KIND.</span></div>
<div class="line"><a name="l00037"></a><span class="lineno">   37</span>&#160;<span class="comment"> * NVIDIA DISCLAIMS ALL WARRANTIES WITH REGARD TO THESE LICENSED</span></div>
<div class="line"><a name="l00038"></a><span class="lineno">   38</span>&#160;<span class="comment"> * DELIVERABLES, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY,</span></div>
<div class="line"><a name="l00039"></a><span class="lineno">   39</span>&#160;<span class="comment"> * NONINFRINGEMENT, AND FITNESS FOR A PARTICULAR PURPOSE.</span></div>
<div class="line"><a name="l00040"></a><span class="lineno">   40</span>&#160;<span class="comment"> * NOTWITHSTANDING ANY TERMS OR CONDITIONS TO THE CONTRARY IN THE</span></div>
<div class="line"><a name="l00041"></a><span class="lineno">   41</span>&#160;<span class="comment"> * LICENSE AGREEMENT, IN NO EVENT SHALL NVIDIA BE LIABLE FOR ANY</span></div>
<div class="line"><a name="l00042"></a><span class="lineno">   42</span>&#160;<span class="comment"> * SPECIAL, INDIRECT, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, OR ANY</span></div>
<div class="line"><a name="l00043"></a><span class="lineno">   43</span>&#160;<span class="comment"> * DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,</span></div>
<div class="line"><a name="l00044"></a><span class="lineno">   44</span>&#160;<span class="comment"> * WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS</span></div>
<div class="line"><a name="l00045"></a><span class="lineno">   45</span>&#160;<span class="comment"> * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE</span></div>
<div class="line"><a name="l00046"></a><span class="lineno">   46</span>&#160;<span class="comment"> * OF THESE LICENSED DELIVERABLES.</span></div>
<div class="line"><a name="l00047"></a><span class="lineno">   47</span>&#160;<span class="comment"> *</span></div>
<div class="line"><a name="l00048"></a><span class="lineno">   48</span>&#160;<span class="comment"> * U.S. Government End Users.  These Licensed Deliverables are a</span></div>
<div class="line"><a name="l00049"></a><span class="lineno">   49</span>&#160;<span class="comment"> * &quot;commercial item&quot; as that term is defined at 48 C.F.R. 2.101 (OCT</span></div>
<div class="line"><a name="l00050"></a><span class="lineno">   50</span>&#160;<span class="comment"> * 1995), consisting of &quot;commercial computer software&quot; and &quot;commercial</span></div>
<div class="line"><a name="l00051"></a><span class="lineno">   51</span>&#160;<span class="comment"> * computer software documentation&quot; as such terms are used in 48</span></div>
<div class="line"><a name="l00052"></a><span class="lineno">   52</span>&#160;<span class="comment"> * C.F.R. 12.212 (SEPT 1995) and is provided to the U.S. Government</span></div>
<div class="line"><a name="l00053"></a><span class="lineno">   53</span>&#160;<span class="comment"> * only as a commercial end item.  Consistent with 48 C.F.R.12.212 and</span></div>
<div class="line"><a name="l00054"></a><span class="lineno">   54</span>&#160;<span class="comment"> * 48 C.F.R. 227.7202-1 through 227.7202-4 (JUNE 1995), all</span></div>
<div class="line"><a name="l00055"></a><span class="lineno">   55</span>&#160;<span class="comment"> * U.S. Government End Users acquire the Licensed Deliverables with</span></div>
<div class="line"><a name="l00056"></a><span class="lineno">   56</span>&#160;<span class="comment"> * only those rights set forth herein.</span></div>
<div class="line"><a name="l00057"></a><span class="lineno">   57</span>&#160;<span class="comment"> *</span></div>
<div class="line"><a name="l00058"></a><span class="lineno">   58</span>&#160;<span class="comment"> * Any use of the Licensed Deliverables in individual and commercial</span></div>
<div class="line"><a name="l00059"></a><span class="lineno">   59</span>&#160;<span class="comment"> * software must include, in the user documentation and internal</span></div>
<div class="line"><a name="l00060"></a><span class="lineno">   60</span>&#160;<span class="comment"> * comments to the code, the above Disclaimer and U.S. Government End</span></div>
<div class="line"><a name="l00061"></a><span class="lineno">   61</span>&#160;<span class="comment"> * Users Notice.</span></div>
<div class="line"><a name="l00062"></a><span class="lineno">   62</span>&#160;<span class="comment"> */</span></div>
<div class="line"><a name="l00063"></a><span class="lineno">   63</span>&#160;</div>
<div class="line"><a name="l00064"></a><span class="lineno">   64</span>&#160;<span class="comment">// Conversion from/to 16-bit floating point (half-precision).</span></div>
<div class="line"><a name="l00065"></a><span class="lineno">   65</span>&#160;</div>
<div class="line"><a name="l00066"></a><span class="lineno">   66</span>&#160;<span class="preprocessor">#define HLF_EPSILON 4.887581E-04</span></div>
<div class="line"><a name="l00067"></a><span class="lineno">   67</span>&#160;<span class="preprocessor"></span></div>
<div class="line"><a name="l00068"></a><span class="lineno">   68</span>&#160;<span class="keyword">typedef</span> <span class="keyword">struct </span>__align__(2) {</div>
<div class="line"><a name="l00069"></a><span class="lineno">   69</span>&#160;   <span class="keywordtype">unsigned</span> <span class="keywordtype">short</span> x;</div>
<div class="line"><a name="l00070"></a><span class="lineno">   70</span>&#160;} half1;</div>
<div class="line"><a name="l00071"></a><span class="lineno">   71</span>&#160;</div>
<div class="line"><a name="l00072"></a><span class="lineno">   72</span>&#160;half1 cpu_float2half_rn(<span class="keywordtype">float</span> f);</div>
<div class="line"><a name="l00073"></a><span class="lineno">   73</span>&#160;</div>
<div class="line"><a name="l00074"></a><span class="lineno">   74</span>&#160;<span class="keywordtype">float</span> cpu_half2float(half1 h);</div>
<div class="line"><a name="l00075"></a><span class="lineno">   75</span>&#160;</div>
<div class="line"><a name="l00076"></a><span class="lineno">   76</span>&#160;<span class="keyword">static</span> __inline__ __device__ __host__ half1 habs(half1 h)</div>
<div class="line"><a name="l00077"></a><span class="lineno">   77</span>&#160;{</div>
<div class="line"><a name="l00078"></a><span class="lineno">   78</span>&#160;    h.x &amp;= 0x7fffU;</div>
<div class="line"><a name="l00079"></a><span class="lineno">   79</span>&#160;    <span class="keywordflow">return</span> h;</div>
<div class="line"><a name="l00080"></a><span class="lineno">   80</span>&#160;}</div>
<div class="line"><a name="l00081"></a><span class="lineno">   81</span>&#160;</div>
<div class="line"><a name="l00082"></a><span class="lineno">   82</span>&#160;<span class="keyword">static</span> __inline__ __device__ __host__ half1 hneg(half1 h)</div>
<div class="line"><a name="l00083"></a><span class="lineno">   83</span>&#160;{</div>
<div class="line"><a name="l00084"></a><span class="lineno">   84</span>&#160;    h.x ^= 0x8000U;</div>
<div class="line"><a name="l00085"></a><span class="lineno">   85</span>&#160;    <span class="keywordflow">return</span> h;</div>
<div class="line"><a name="l00086"></a><span class="lineno">   86</span>&#160;}</div>
<div class="line"><a name="l00087"></a><span class="lineno">   87</span>&#160;</div>
<div class="line"><a name="l00088"></a><span class="lineno">   88</span>&#160;<span class="keyword">static</span> __inline__ __device__ __host__ <span class="keywordtype">int</span> ishnan(half1 h)</div>
<div class="line"><a name="l00089"></a><span class="lineno">   89</span>&#160;{</div>
<div class="line"><a name="l00090"></a><span class="lineno">   90</span>&#160;    <span class="comment">// When input is NaN, exponent is all ones and mantissa is non-zero.</span></div>
<div class="line"><a name="l00091"></a><span class="lineno">   91</span>&#160;    <span class="keywordflow">return</span> (h.x &amp; 0x7c00U) == 0x7c00U &amp;&amp; (h.x &amp; 0x03ffU) != 0;</div>
<div class="line"><a name="l00092"></a><span class="lineno">   92</span>&#160;}</div>
<div class="line"><a name="l00093"></a><span class="lineno">   93</span>&#160;</div>
<div class="line"><a name="l00094"></a><span class="lineno">   94</span>&#160;<span class="keyword">static</span> __inline__ __device__ __host__ <span class="keywordtype">int</span> ishinf(half1 h)</div>
<div class="line"><a name="l00095"></a><span class="lineno">   95</span>&#160;{</div>
<div class="line"><a name="l00096"></a><span class="lineno">   96</span>&#160;    <span class="comment">// When input is +/- inf, exponent is all ones and mantissa is zero.</span></div>
<div class="line"><a name="l00097"></a><span class="lineno">   97</span>&#160;    <span class="keywordflow">return</span> (h.x &amp; 0x7c00U) == 0x7c00U &amp;&amp; (h.x &amp; 0x03ffU) == 0;</div>
<div class="line"><a name="l00098"></a><span class="lineno">   98</span>&#160;}</div>
<div class="line"><a name="l00099"></a><span class="lineno">   99</span>&#160;</div>
<div class="line"><a name="l00100"></a><span class="lineno">  100</span>&#160;<span class="keyword">static</span> __inline__ __device__ __host__ <span class="keywordtype">int</span> ishequ(half1 x, half1 y)</div>
<div class="line"><a name="l00101"></a><span class="lineno">  101</span>&#160;{</div>
<div class="line"><a name="l00102"></a><span class="lineno">  102</span>&#160;    <span class="keywordflow">return</span> ishnan(x) == 0 &amp;&amp; ishnan(y) == 0 &amp;&amp; x.x == y.x;</div>
<div class="line"><a name="l00103"></a><span class="lineno">  103</span>&#160;}</div>
<div class="line"><a name="l00104"></a><span class="lineno">  104</span>&#160;</div>
<div class="line"><a name="l00105"></a><span class="lineno">  105</span>&#160;<span class="keyword">static</span> __inline__ __device__ __host__ half1 hzero()</div>
<div class="line"><a name="l00106"></a><span class="lineno">  106</span>&#160;{</div>
<div class="line"><a name="l00107"></a><span class="lineno">  107</span>&#160;    half1 ret;</div>
<div class="line"><a name="l00108"></a><span class="lineno">  108</span>&#160;    ret.x = 0x0000U;</div>
<div class="line"><a name="l00109"></a><span class="lineno">  109</span>&#160;    <span class="keywordflow">return</span> ret;</div>
<div class="line"><a name="l00110"></a><span class="lineno">  110</span>&#160;}</div>
<div class="line"><a name="l00111"></a><span class="lineno">  111</span>&#160;</div>
<div class="line"><a name="l00112"></a><span class="lineno">  112</span>&#160;<span class="keyword">static</span> __inline__ __device__ __host__ half1 hone()</div>
<div class="line"><a name="l00113"></a><span class="lineno">  113</span>&#160;{</div>
<div class="line"><a name="l00114"></a><span class="lineno">  114</span>&#160;    half1 ret;</div>
<div class="line"><a name="l00115"></a><span class="lineno">  115</span>&#160;    ret.x = 0x3c00U;</div>
<div class="line"><a name="l00116"></a><span class="lineno">  116</span>&#160;    <span class="keywordflow">return</span> ret;</div>
<div class="line"><a name="l00117"></a><span class="lineno">  117</span>&#160;}</div>
<div class="line"><a name="l00118"></a><span class="lineno">  118</span>&#160;</div>
<div class="line"><a name="l00119"></a><span class="lineno">  119</span>&#160;} } <span class="comment">// namespace</span></div>
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